Claude Sonnet 4.5 vs Claude Sonnet 4.5 Turbo: which model should you choose?
We compared Claude Sonnet 4.5 and Claude Sonnet 4.5 Turbo on price, context window and 12 benchmarks. Claude Sonnet 4.5 has the stronger average benchmark score; Claude Sonnet 4.5 is cheaper on a blended 3:1 basis.
Claude Sonnet 4.5
Claude Sonnet 4.5 is a frontier model from Anthropic. It offers a 400,000-token context window, costs $17.84 per million input tokens and $70.50 per million output tokens, and averages 86.0 across the index's benchmark suite.
- Input
- $17.84 / 1M
- Output
- $70.50 / 1M
- Context
- 400,000
- Avg score
- 86.0
- Open weights
- No
Claude Sonnet 4.5 Turbo
Claude Sonnet 4.5 Turbo is a frontier model from Anthropic. It offers a 1,000,000-token context window, costs $18.37 per million input tokens and $81.65 per million output tokens, and averages 85.9 across the index's benchmark suite.
- Input
- $18.37 / 1M
- Output
- $81.65 / 1M
- Context
- 1,000,000
- Avg score
- 85.9
- Open weights
- No
Specification comparison
| Spec | Claude Sonnet 4.5 | Claude Sonnet 4.5 Turbo | Edge |
|---|---|---|---|
| Input price / 1M | $17.84 | $18.37 | A |
| Output price / 1M | $70.50 | $81.65 | A |
| Context window | 400,000 | 1,000,000 | B |
| Max output | 128,000 | 65,536 | A |
| Average score | 86.0 | 85.9 | A |
| Arena Elo | 1478.2 | 1461.7 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Sonnet 4.5 wins 4, Claude Sonnet 4.5 Turbo wins 8, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Sonnet 4.5 | Claude Sonnet 4.5 Turbo | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 88.0 | 87.2 | 0.8 | Claude Sonnet 4.5 |
| GPQA Diamond | 82.6 | 83.7 | 1.1 | Claude Sonnet 4.5 Turbo |
| SWE-bench Verified | 74.2 | 75.2 | 1.0 | Claude Sonnet 4.5 Turbo |
| HumanEval | 92.7 | 90.4 | 2.3 | Claude Sonnet 4.5 |
| MATH-500 | 87.0 | 88.0 | 1.0 | Claude Sonnet 4.5 Turbo |
| AIME 2025 | 86.3 | 87.8 | 1.5 | Claude Sonnet 4.5 Turbo |
| LiveCodeBench | 82.5 | 78.9 | 3.6 | Claude Sonnet 4.5 |
| IFEval | 91.1 | 91.4 | 0.3 | Claude Sonnet 4.5 Turbo |
| TruthfulQA | 87.2 | 87.7 | 0.5 | Claude Sonnet 4.5 Turbo |
| HellaSwag | 93.0 | 93.9 | 0.9 | Claude Sonnet 4.5 Turbo |
| MMMU | 80.9 | 81.1 | 0.2 | Claude Sonnet 4.5 Turbo |
| Arena Elo | 1478.2 | 1461.7 | 16.5 | Claude Sonnet 4.5 |
Price analysis
On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 costs about $31.00 per million tokens and Claude Sonnet 4.5 Turbo costs about $34.19. Claude Sonnet 4.5 is roughly 9% cheaper than Claude Sonnet 4.5 Turbo. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Claude Sonnet 4.5 Turbo has the larger context window at 1,000,000 tokens, compared with 400,000 for Claude Sonnet 4.5. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Sonnet 4.5 wins 4, Claude Sonnet 4.5 Turbo wins 8, and 0 are tied. On the index average, Claude Sonnet 4.5 leads Claude Sonnet 4.5 Turbo by 0.1 points (86.0 versus 85.9).
The price picture favours Claude Sonnet 4.5. The context picture favours Claude Sonnet 4.5 Turbo. Those two dimensions often matter more than a few benchmark points once a model is good enough for the task.
If you need a single default, start with Claude Sonnet 4.5 for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude Sonnet 4.5 if
- You want the higher average benchmark score in this index.
- Unit cost matters and you want the cheaper blended price.
- You need the larger 128,000-token output limit.
Choose Claude Sonnet 4.5 Turbo if
- You need the larger 1,000,000-token context window.
FAQ
Is Claude Sonnet 4.5 better than Claude Sonnet 4.5 Turbo?
On the index average, Claude Sonnet 4.5 leads Claude Sonnet 4.5 Turbo by 0.1 points (86.0 versus 85.9). The better choice depends on price, context and your task. Claude Sonnet 4.5 wins 4 benchmarks, Claude Sonnet 4.5 Turbo wins 8.
Which is cheaper, Claude Sonnet 4.5 or Claude Sonnet 4.5 Turbo?
Claude Sonnet 4.5 is cheaper on a blended 3:1 basis at about $31.00 per million tokens, versus $34.19 for Claude Sonnet 4.5 Turbo.
Which has the larger context window?
Claude Sonnet 4.5 Turbo has the larger context window at 1,000,000 tokens. Claude Sonnet 4.5 has 400,000 tokens.
Are these models open weights?
Claude Sonnet 4.5 is proprietary; Claude Sonnet 4.5 Turbo is proprietary.
Which should I choose for production?
If you need a single default, start with Claude Sonnet 4.5 for quality-sensitive work, and check whether its price holds at your expected volume before committing.